Petrochemical products such as oil and gas, are ubiquitous in society and can be found in everything from gasoline to children's toys. Because of this, the demand for oil and gas remains high. In order to meet this high demand, it is important to locate oil and gas reserves in the Earth. Scientists and engineers conduct “surveys” utilizing, among other things, seismic and other wave exploration techniques to find oil and gas reservoirs within the Earth. These seismic exploration techniques often include controlling the emission of seismic energy into the Earth with a seismic source of energy (e.g., dynamite, air guns, vibrators, etc.), and monitoring the Earth's response to the seismic source with one or more receivers (e.g., geophones, hydrophones, accelerometers, etc.). By observing the reflected seismic signals detected by the receiver(s) during the survey, the geophysical data pertaining to reflected signals may be acquired and these signals may be used to help create an image of the subsurface of the earth and/or to indicate the composition of the Earth proximate to the survey location.
Geophysical exploration surveys are often conducted over large areas of land or water, often tens, hundreds, or even thousands of square miles. Traditionally, marine surveys are conducted in a “racetrack” manner, where a vessel acquires seismic data in relatively straight sail lines; for example, a vessel may acquire a first portion of seismic data by traveling directly southbound along a first line, turn (thereby displacing the vessel either east or west), acquire a second portion of seismic data by traveling northbound along a second line, turn again (again displacing the vessel to the east or west), acquire a third portion of seismic data by traveling along a southbound third line, and so forth; leaving a trail reminiscent of a racetrack. The racetrack methodology theoretically allows a vessel to cover the most area in the least amount of time.
During acquisition, many factors impact the quality of the data that is acquired and the time that it takes to acquire the data. For example, again in the marine context, sea currents, bad weather, swell noise, seismic interference, other vessels in the area, equipment problems, and so forth, may cause imperfections or anomalies in the acquired data. In some instances, data may not be collected at all for certain coordinates (because, for example, sea currents pushed a seismic receiver out of its intended path), or the data may have so much noise or other problems so as to be unusable. In these cases, the holes in data coverage may need to be rectified by conducting “infill,” which may involve a repeat trip by a vessel to the same area. Since conventional geophysical seismic surveys often cost thousands or tens of thousands of dollars per hour to complete, repeating the survey to infill data can be costly. Therefore, methods and apparatuses are desired that facilitate determination of locations to acquire data in order to increase the quality of data acquired and reduce costs associated with conducting the surveys.